Natural variation of biomass yield and nutrient dynamics in Miscanthus

Abstract

Miscanthus has been rated as one of the most promising bioenergy crops due to its potential for biomass production. The sustainable production of Miscanthus for bioenergy feedstock partly depends on the varieties that are efficient in terms of nutrient use for the production of biomass. In this study, 23 Miscanthus accessions, collected from wide range of geographic regions, were established early in March 2010 in Wuhan, China. The feedstock was sampled for nutrient concentration determination late in November 2010 and 2011 (at physiological maturity), and harvested early in February 2011 and 2012 (after a killing frost) to evaluate the biomass yield, nutrient concentration and removal. Across these two years, the biomass yield was negatively related to the latitude of the original collection sites. A significant increase in biomass production was observed in the second growth year relative to that in the first growth year among almost all of the Miscanthus accessions. The accessions of MS267 and MS321 only yielded 1.32 and 1.91tonha−1 in 2010, respectively, but the biomass yield increased dramatically to 11.23 and 22.76tonha−1 in 2011, leading to greater nutrient removal by the final harvest and thus the requirement of much more fertilizer in the following years. The accessions MS92, MS145, MS262, MS436 and MS438 established poor biomass yields, averaging <1tonha−1 in the first two years, which suggests that they may be unsuitable for planting in the present environment. Significant differences between accessions were found for the nutrient concentration at maturity and after frost. Notable differences in the nutrient concentration after frost and nutrient removal were presented among the Miscanthus accessions. In addition, the significant difference conferred the possibility of achieving a desirable cultivar with significant biomass yield and relative nutrient removal by harvest. The accessions MS434, MS461 and MS296 had consistently high biomass yield and relatively low nutrient removal, demonstrating desirable characteristics as a low-input bioenergy crop. The results are important for guiding the agronomical practices of nutrient management and genetic improvement for nutrient-use efficiency to increase biomass production with low fertilizer input.